Why would an enigne chew through turbo's?...

[Rawze]

Why would an enigne chew through turbo's?...

- This is the question that Yiyto's turbo shop (Griffin, GA) has asked me, and what to look for on the engine to prevent it after a turbo gets rebuilt/replaced.

I am posting this here for myself, and for others to join in and give some suggestions, opinions, etc.. so that he can make a list o f things to check for on the engine/truck when someone gets a turbo replaced, to prevent a repeated failure.

Here is a list of causes I got off the top of my head so far...

== #1 first and foremost ... the typical 90%+ of BAD DELETE PROGRAMMING that is seen time and again around here. Simply having the de-mandate programming reviewed to see if the turbo (and the rest of the ecm) has been properly re-programmed will prevent this.

== Deleted enignes where there is no block-plate between the exhaust manifold and turbo. OR. Engine with a whole lot of miles on it and the egr cooler is getting clogged ... Carbon builds up in the egr cooler after several years, it hardens, and spits back out randomly as hard chunks ... destroying the turbine blade(s) and/or hanging up the VG mechanism as they go thru the turbo. This typically causes repeated turbo failures. - I have seen people go thru 3 or 4 turbo's in a row in short succession because of this before they realize this is the actual problem.

== Very dirty intake filters. Causing over-spooling of the turbo all the time. Dirty intake filter makes the turbo speed up and work harder to get the right amount of air at the intake manifold.

== Aftermarket CAC unit. <- Some brands (like duras$it and others) of after-garbage charge air coolers are VERY RESTRICTIVE, and cause the turbo to speed up and work harder to get the right boost st the intake. This is another quite common problem that i have seen.

== CAC and/or other boost leaks on the intake. Loosing boost pressure due to bad CAC, bad boots on the intake, etc.. cause the turbo to speed up and work harder to get the right boost st the intake.

== Oil flow restrictions thru the turbo and top end of the engine. - It is VERY EASY for the turbo to get starved of oil and/or for it to bleed oil into the CAC or exhaust if there is any kind of crank case pressure buildup in the engine at all. Having a clogged up crank case filter, or one that cannot keep up with blo-by on an older engine will certainly take out a turbo, or cause it to bleed oil, and also cause the top-end of the engine ti run dry, chewing up overhead cams/rockers, etc.

== ANY type of exhaust restriction... deleted or not. On a deleted engine, some moron only drilling holes thru the elements instead of gutting all of them 100% to the bare metel. Morons who think they can ignore the SCR unit like a fool (after a delete) and not hollow it out 100% properly as well. - AND/OR-- Deleted or not... if the decomp tube gets clogged up partially due to seeping def fluid (known as the volcano problem listed here: http://rawze.com/forums/showthread.php?t...07#pid1807

== Excessive positive pressure all the time at the intake on non-deleted enignes.. causing the infamous 'turbo cough' when you get on it hard, or sitting there at idle. This happens when sensors are reading badly and/or the egr curcuit and sensors are full of soot. This also happens with bad delete programming where things were not shut off properly.

== bad IMAP, EGR delta-P sensor (of clogged passageways for Delta-P), and other egr-tune-up /egr soot buildup related problems.

== excessive heat form someone turning up the power.. and or exceeding the turbo's flow ratings (due to jacking the power above turbos ratings) .. and there is not enough cooling around the turbo externally to wick it away.

== heavy haul applications where the wrong turbo was used (non titanium model) .. and/or where there is simply not enough air flow around the engine and trubo to keep up with this type of torture.

== RV and buss applications where there is simply not enough air flow around the engine and turbo to keep up with this type of torture. This especially on RV's where they tend to jack the power all the way up even from the factory.. to 'brag about its power and sell more units'.

That is what I got so far just thinking about it ... can anyone think of more scenarios?...